An unexpected encounter with wake turbulence can result in possible loss of control, with possible concomitant injury to crew and passengers, typically during all phases of flight. These encounters occur many times every year.
In general, the smaller the following aircraft, the larger the disturbance when experiencing a fly through wake situation. There have been fatal accidents in the past, which later resulted in greater aircraft separation standards air traffic authorities.
The display of a possible wake turbulence ahead would be a great tool for the pilot. U.S. Pat. No. 7,411,519 granted to Honeywell on Jun. 2, 2002 describes one method to create such a cockpit display.